Dear Don,
> Recently, I have been doing the DOSY experiment using XWINNMR 3.5. I
> was having trouble with the data processing until I discovered that the
> numbers in the difflist file gave incorrect values for the gradient
> strength. I found that if I edited difflist and shifted the decimal
> point 2 positions (multiplied by 100) I was able to reprocess the data
> and obtain results that made sense. I checked the
> /u/conf/instr/gradient_calib file and it contained the correct value for
> maximum gradient strength, assuming that the units are G/mm.
>
> Is it possible that there is something else that I have overlooked in
> configuring the software for this experiment, or is it possible that
> this is an idiosyncrasy with this version of the software?
There was a XWinNMR version where the shape "SINE.100" (and probably
others as well) contained a wrong integral value (what surprise, it
was wrong by a factor of 100). The right entry in a sine shape file
should be:
##$SHAPE_INTEGFAC= 6.302007e-01
The easiest is to use a text editor and just correct it. This was
actually a bug in shapetool, so using shapetool to recalculate the
shape might lead again to the wrong value.
After that you can recalculate the 'difflist' by calling:
"dosy restore".
Best Regards
Rainer
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Dr. Rainer Kerssebaum Dr. Rainer Kerssebaum
NMR Applikation NMR Applications
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